Centrifugal bepaeatob



Feb. 14, 1939.

ATTORNEY.

Patented Feb. 1 4, 1,939` i UNITEDsTATEs 2,141,414 REISS'U ED anun CENTRIFUGAL SEPABATOB Laurence P. 'Sbarpled Ardmore, Pa., assignor to The Sharples Specialty Company, Philadelphia,

Pa., a corporation of Delaware Application February 25,

' ,7 claims.

The present invention pertains.l to the centrifugal dehydration o1' solids and relates particularlyjy'to the provision ofV a centrifugal separator of improved construction designed to eiect removal of liquid from solids. An example of a separating operation for which the machine of the invention is especially suitable is the sepa-` ration of mother liquor from crystals :formed by the ycooling of such liquor.

A diiiicult problem has been encountered'in the operation of machines of the prior art del signed to perform separating functions of this character by reason of the tendency oi solids discharged from the centrifugal rotor to adhere to surfaces which they strike after such discharge. in many cases, a part of the solids discharged progressively build up in the form of a cake to such an extent as to effectively block further discharge Yof solids from the rotor. The present invention is particularly concerned 4 with the avoidance oi this tendencyoi discharged solids to adhere to impacted surfaces.

This object is achieved by the provision of a special design oi receiving and deiiecting memher adapted to receive and discharge solids leavingl the centrifugal rotor.` Reference is made to the attached drawing for illustration oi' the details of the invention-and its principle of operation. In that drawing, the single ugure illustrates the parts associated with the rotor and uppery end of a centrifugal separator illustrating the invention.,l the view being partly in cross section and partly in side elevation.

Referring to the drawing by reference characters, a rotor it is illustrated which affords a plurality oi' successive separating stages. The general features of design of the machine by which thesolids 'are dehydrated and discharged from the upper end ii -of the rotor may be of any known character, but these features are preierably similar to those illustrated in my co-pending application for Machine and method for separating solids from liquids, Serial No. 728,269,

filed May 3l, i934. The dehydrated solids are preferably discharged from the rotor by means of a plurality of plows IZ-which. are arranged at an angle to the wall of the rotor and rotated at a speed slightly diderent from that of the rotor in order to discharge the solids in a manner well understoodin this art. Reference is made to the patentto Brewer No. 1,991,490 for a more detailed description of the construction and principle of operation of plows of this character. Features of rotor and plow design form no part ofthe present invention.

1936, Serlal No. 65,544

(Cl. 21o-73) A stationary casing I3 surrounds the rotor and receives the liquid discharged therefrom through openings I9 provided in the wall of the rotor. The novel features of the invention consist in 'a novel member I4 for receiving and dlscharg-k 5' ing solids projected in a substantially tangential direction from the inner circumference of the vupper end il of the rotor. In the form o1' the invention illustrated in the drawing, this novel receiving and discharging member is illustrated 10 as formed integrally with the casing ,13, but it is to be understoodthat the invention is in no way limited to such integral formation of such receiving and deecting member. As illustrated inthe drawing, this novel member constitutes le flange it whose upper surface .lies in substantlally the same plane as the plane of discharge of solids in the upper end li oi the rotor, (horizontally, as illustrated), cylindrical deiiector surface il at the outer circumference of thehcrig@ aontaily extending flange it extending substantially at right angles to the plane of discharge' and an overhanging lip it at the upper extremity of the cylinder ill.

An important feature ci .the invention consists 25 in the :tact that the ange it is of relatively narrow width and that the surface i'i forming a continuation of the ange it accordingly lies in close proximity to the circumference of the rotor, and accordingly has a radius oi curvature 3@ but slightly larger than Athat of the rotor. y Experience hasfdenicnstrated that this relatively simple form ci deector member avoids the dimculties discussed above incident to adhesion of discharged solids to surfaces impacted 35 .by such `discl'narged solids in the operation ci centrifugal extractor-s of this general type in prior art practice. in the operation of the machine illustrated in the drawing, solids discharged from the rapidly rotating rotor it are projected in a 4@ upper wall ii of the rotor which is substantially 4 tangential to the circumference of that Wall.

In view of the fact that the vertical wall of the surface il of the deflecting and discharging tu member it is arranged in close proximity Ato the upper wall il of the rotor, the circumference of the surface il is but slightly larger than that of the upper wall il ofthe rotor. In view oi this fact, solids discharged tangentially from the d@ upper wall of the rotor will strike the surface il?` almost tangentially with respect to that wall; l

i. e., the angle at which such solids will strike the-wall in question is so slight that the solidsl will not cling to it. The fact that the wall I1 5d direction from the inner circumference ci the extends at right angles to the plane of discharge of solids causes a retardation of the solids by friction prior to their discharge over the wall and the provision of the inwardly extended lip or flange I8 also retards the tendency of these solids to be discharged over that wall. As the result of these two features of construction, the solids after discharging from the rotor run for some distance around the circumference of the surface I'l where they lose velocity due to friction. They are then smoothly impelled over the flange I8 and outwardly into the zone between the casing I3 and the surrounding housing I5.

Another factor which is believed to contribute to the advantageous result attained consists in the fact that the substantially tangential discharge of solids against the inner wall of the flange I1 effects an action analogous to sandblasting in removing previously discharged solids which may have adhered to that flange. The arrangement of the ange in question as illustrated in the drawing contributes importantly to this function, for the impingement of solids against the inner surface of the iiange at only a slight angle with respect to that surface assists in the dislodgrnent of adhering solids and the fact that the flange I1 is very close to the upper wall I I of the rotor also assists in this dislodging function because of the fact that the discharged solids strike the flange I1 before they have lost substantial velocity by air friction or otherwise, and these discharged solids accordingly strike the ange with sufficient force to dislodge any solids which may previously have adhered thereto.

The ratio of the diameter of the inner wall of the flange I'l to that of the inner surface of the portion of the wall I I of the rotor from which the solids are discharged is preferably 3:2 or less and in the best form of the invention it is 6:5 or less. Excellent commercial results have been obtained in the discharge of dehydrated ammonium sulphate crystals by a centrifuge constructed in accordance with the invention in which the diameter of the circle described by the crystal discharging extremity ofthe wall II was i3 inches and the diameter of the circle described by the inner surface of the ange I1 was 141/2 inches.

Modifications will be obvious to those skilled in the art and I do not therefore wish to be limited except by the scope of the sub-joined claims.

I claim:

1. A centrifugal separator comprising a centrifugal rotor adapted to effect dehydration of solids and radial discharge of such solids from the rotor in a substantially horizontal plane under the influence of centrifugal force during .the rotation thereof, and a solids receiving member having a concentric wall surrounding the solids discharging surface of the rotor over which wall solids are adapted to be discharged, said wall extending upwardly from the plane of the rotor discharge and substantially at right angles thereto and having a radius of curvature'at all solids receiving points thereof which is but slightly larger than the radius of curvature of the solids discharging surface of the rotor, and being of sufficiently small height to permit the discharge of solids upwardly thereover.

2. A centrifugal separator comprising a cent- -trlfugal rotor adapted to eiect dehydration of solids and discharge of such solids from the rotor in a substantially horizontal plane under the influence of centrifugal force during the rotation thereof, and a solids receiving' member having a substantially vertical concentric wall surrounding the solids discharging surface of the rotor over which wall solids are adapted to be discharged, said wall extending upwardly from the plane of the solids discharging surface of the rotor and having a radius of curvature at all solids receiving points thereof which is but slightly larger than the radius of curvature of the solids discharging surface of the rotor, and being of sufdciently small height to permit the discharge of solids upwardly thereover.

3. A centrifugal separator comprising a centrifugal rotor adapted to effect dehydration of solids and discharge of such solids from the rotor in a substantially horizontal plane under the infiuence of centrifugal force during the rotation thereof, and a solids receiving member having a solids supporting surface substantially parallel to the plane of discharge of the solids and immediately beneath said plane and a wall over which solids are adapted to be discharged form.- ing a continuation of said solids supporting surm face and extending upwardly at an angle with respect to said solids supporting surface, said wall being substantially concentric with the solids discharging surface of the rotor and lying in close proximity thereto, and being of sufficiently small height to permit the discharge of solids upwardly thereover.

4. A centrifugal separator comprising a centrifugal rotor adapted to effect dehydration of solids and discharge of such solids from the rotor in a substantially horizontal plane under the influence of centrifugal force during the rotation thereof, and a solids receiving member having a solids supporting surface substantially parallel to the plane of discharge of the solids and immediately beneath said plane and a wall over which solids are adapted to be discharged forming a continuation of said, solids supporting surface and extending upwardly and substantially vertically, said wall being substantially concentric with the solids discharging surface of the rotor and lying in close proximity thereto, and being of sufficiently small height to permit the discharge of solids upwardly thereover.

5. A centrifugal separator comprising a centrifugal rotor adapted to effect dehydration of wlids and discharge of such solids from the rotor in a substantially horizontal plane under the infiuence of centrifugal force during the rotation thereof, and a solids receiving member having a solids supporting surface substantially parallel to the plane of discharge of the solids and immediately beneath said plane, a wall over vwhich solids are adapted to be discharged forming a continuation of said solids supporting surface and extending upwardly at an angle with respect to said solids supporting-surface, said wall being substantially concentric with the solids discharging surface of the rotor and lying in close proximity thereto and having an overhanglng annular ange extending radially inwardly from the uppermost surface thereof, and being of suillclentlysmall height to permit the discharge of solids upwardly thereover.

6. A centrifugal separator comprising a centrifugal rotor adapted to effect dehydration of solids and discharge of such solids from the rotor in a substantially horizontal plane under the influence of centrifugal force during the rotation thereof, and a solids receiving member having a solids supporting surface substantially parallel to the plane of discharge of the solids and immediately beneath said plane, a wall over which solids are adapted to be discharged forming a continuation of said solids supporting surfacel and extending upwardly and substantially vertically, said wall being substantially concentic with the solids discharging surface of. the rotor and lying in' close proximity thereto, and being of sufficiently small height to permit the discharge of `solids upwardly thereover, and an overhanging annular flange extending radially inwardly from the uppermost surface of said wall.

7. A centrifugal separator comprising a ,centrifugal rotor adapted to effect dehydration of solids and discharge of such solids from the rotor LAURENCE P. sHARPLEs. 

